Tank car structure



June 28, E Y

TANK CAR STRUCTURE Filed March 20, 1931 [NgiEg OR J WM Patented June 28, 1932 UNITED i s-T TE S LOUIS E. ENDSVLEYI,VOF rzrrsnuaen, IBENNSYLVANIA TANK can s'rrwcruan Application filed March 20, 1931 Serial No. 523,970.

My invention relates to railway tank car structures and more particularly to the body portions thereof.

In this application, I describe and claim J: a structure constituting an improvement displacement of the liquid lading'.

upon my Patent No. 1,790,855, issued February 3, 1931. In said patent, a dome is shown at each end of a tank car, the arrangement being such that upon impacts orshocks-resulting during transportation or switching of the cars, portions of the liquid contents will enter one of the domes, thus permitting temporary displacement of'substantially the entire liquid contents of the 'car body, and also providing an air cushion'in thedome. Thus, if the forward movement of a-car is suddenly checked, the liquid contents thereof will tend to shift toward the front end of the car, but the usual thrust resulting from such tendency will be reduced or counteracted, by reason of the fact that a portion of the liquid willbe deflected into the dome at the front end of the car, and atthe same time, be cushioned by the entrapped air within the dome. The dome at the other end of thecar will serve a similar function'when thrusts occur in the opposite direction. One object of the present inventionis t provide means for venting the said domes near the ends of the cars to the atmosphere, at points remote from the domes themselves, to thereby permit of'the establishment of greater air pressurewithin these domes upon Another objectfof this invention is to provide means for more efl'ectively entrapping or confining air within the said domes.

A further object of invention is to provide means for reducing reactive forces within the tank body, after the liquid lading has been displaced in one direction through bufiing stresses on the car body. 7

Still another object of my'inventionis to provide a tank car structure of generally simplified and improved form. 5

Some of the forms hich my invention may take are shown in'the accompanying drawing, wherein Figure 1 is a side elevational view of a railway tank car; Fig. 2 is a fragmentary sectional view thereof, on an enlarged scale Fig.3 is a view taken on the line IIIIII of Fig. 2; Fig. 4 is a view ta-k en on the line IV 1V of Fig. 2, and Fig. 5 shows a modification of the structure of Fig. 3.5

Reference is made tothespecification of my previous patent forvarious details re.- garding the extent of yielding resistance of fered to shocks resulting from buiiing strains, and theyneed not be hererepeated.

. The car is shown-as havingan under frame 6, draft gears and trucks which may be of the usual construction. However, the car body or tank 7 not only has the usual central dome 8, but end domes 9 and'lOQ, The. dome 8is' providedwith the usual relief valve 11 anda valve-controlled drain pipe 12 is providedat the bottom of the car body. C l

The domes 9 and communicate w'ith the interior of the tank 7 but are closed at their upper portions, to permit the effective confinement of air within the domes when endwise thrusts on the car cause displacement of the liquid contents ofthe car. In normal use, the tank 7 is completely filled with liquid except for the spaces within the domes, so that when an endwise thrust is imposed on the car, sayfrom the left hand end toward the right hand end thereof, a portion-,o f the liquid will'be caused to enterthe dome 10, thus permitting some displacement of substantially the entireliquid contents ofthe tank.

y This displacement of the liquid is' yield- J c v ably resisted by the weight of the, liquid which enters the dome 10 and by the cushioning efiect of the'air entrapped within the dome; A similar effect will be produced by the dome 9 when endwise thrustsareimposedin the opposite direction;

It is desirable that gases be vented from thedomes 9 and 10, without'materially affecting their air-confining. functions. To this end, I provide pipes 14 each of which communicates at its ends with the lower'portion of one of the domes 9 and I0, and atits other end with thedome 8, 1 3 p These pipes are preferably positioned slightly above the. normal :liquid level but may be slightly below such level and still permit the venting of gasesfrom the domes sides of the domes which lie-next to the mid portion of the car. These plates 15 are of narrow vertical width and short length relative to the diameter of the car, so -that they will not unduly restrict movement of the liquid ladin'g, but will overcome tendency of the air to be forced from the dome toward the central portio'nofthe car in the direction indicated by the arrow 16 in Fig. 2. .v

' In order to reduce'reactive force following an end thrust on the car, I provide in each of the domes 9 and 10 hinged plates 17 and 18 that function as flap valvesor checkvalves. These plates are/normally held against their seats 19 and'20, respectively, by'springs 21, that are carried by pintles or rods 22 upon which the valves are'pivotallymounted. I

The valves '17 and '18 are moved upwardly by'fiow of liquid into the domes, as indicated by'dotted lines in'Fig. 2, the springs'21 returning the valves to their closed positions quickly after flow of fluid into the domehas stopped, thus confining a volume of liquid within the dome and preventing it suddenly flowing back to the body of the tank car under'the action of gravity'and by the pressure of the confined air. The entrapped liquid will be perinitted to return slowly to the main body of liquid by leakage past the valves 17 and 18. p 7

It will be obvious that the normally reac' 'tiveforces are thusmateria'lly reduced or retarded. I v

As the pipes 14 are connected to the end domes below the check valves, there will be no surge of liquid therethrough from the end domes, except the blow be a very small one. That is, if under a heavy blow, the retaining valves trap a large percentage of oil and a low v'olume of air or gas, this will notflow intothe center dome. Of course, under the initialimpact or under very small impacts,

produced.

orat the beginning of the large impact, there may be some liquid and a small amount of gas flow back into the pipe 14, but when the pipe 14 fills up to the center dome, the liquid moving forward from the other end of the car will have the same retaining force as onehalf the contents of the car woul'd have, be-

cause the liquid is all tending to 'go' in the same direction and therefore will have the 's'aine pressure at the forward'dome end as the liquid has underneath, and no flow will be Referringnow'to Fig..5, I"show a dome similar to the domes 9 and 10, but which is provided with a series of check valves 24 instead of the flap valves 17 and 18. These valves 24 are yieldably held against their seats by means of springs 25 interposed between the heads of the valve stems and the valve stem guides 26. A dished plate 27 is secured in the dome and provided with cutout portions that serve as passageways for liquid entering the dome, and the plate serving 'as a'seat for the valves 24. The plate 27, being dished downwardly, has greater strength to resist pressure from Within the dome than if it were flat.

The check valves 24 in one of the end domes will, of course, be moved. upwardly if an impact of sufficient force is imposed against either end of the car, and oil will surge or move up through these check valves 24. If this blow issutficient to cause the oil to go up under a heavy pressure, when the force is removed from that end of the car, a surge would be produced by this entrapped air or gas, but forthe Check valves which will immediately close upon a reverse movement of the liquid, and they will hold this entrapped airor gas for a su'liicient time to prevent a surge toward the other dome. This air pressure can be relieved gradually b-y'predetermined sizes of holes in the check valves or in thevplate 27.

As the rules or requirements for tank cars specify a given percentage of open space'in the dome above the liquid, by the use of pipe 14 from the two end domes to the center dome, the center dome can be much smaller than now made, because of the extra capacity furnished by the two end domes. I contemplate also that the central dome may be provided with check valves similar to the valves of Figs. 2 to- 5, where conditions render such structure desirable.

I claim as my invention 1. A. vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a dome "extendingfupwardly from a point adjacent to each end of the said body, the said domes having communication with the interior of the. body to permit displacement of liquid lading, andcheckvalVe devices permit-ting;

relatively. free flow of liquid into said domes, but retarding backflowi therefrom.

2. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a dome extending upwardly from apoint adjacent to each end of'the said body, the said domes having communication with. the interior of the body to permit displacement of'liquid lading, andvent pipes each connected at one "end tothe lower portion of one of the domes and 'havingimeans ad acent to its other end for communication with the, atmosphere.

, A vehicle having ,aytank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a dome extending upwardly from a point adjacent to the middle of the body, a dome extending upwardly from a point adjacent to each end of the said body, pipes communicating with the lower portions of the last-named domes and with the first-named dome, and a venting device on the first-named dome.

4. A vehicle having a Itank-like body of elongated form disposed in parallelism With the line of movement of the vehicle, a dome extending upwardly from a point adjacent to the middle of the body, a dome extending upwardly from a point adjacent'to'each end of the said body, pipes communicatin with the lower portions of the last-named domes, and with the lower portion of the first-named dome.

5. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a chamber for confining air and for utilizing the said air to cushion movement of liquid within the said body, the said chamber communicating with the interior of said body and being of sufficient area to permit displacement of such quantity of liquid lading as to materially dampen bufling forces, and a baffle plate depending from a point adjacent to the lower end of the chamber, the plate being of small vertical dimension relative to the diameter of the tank.

6. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a chamber for confining air and for utilizing the said air to cushion movement of liquid within the said body, the said chamber communieating with the interior of said body'an'd being of suflicient area to permit displacement of such quantity of liquid lading as to materially dampen buffing forces, and a baffle plate depending from a point adjacent to the lower end of the chamber, the plate being of narrow width relative to the diameter of the tank, and disposed transversely of the car body, the shortest distance between the ends of the plates being not materially in excess of the diameter of the chamber.

7. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a chamber for confining air and for utilizing the said air to cushion movement of liquid within the said body, the said chamber communicating with the interior of said body and being of sufficient area to permit displacement of such quantity of liquid lading as to materially dampen buffing forces, and a baflie plate depending from a point adjacent to the lower end of the chamber, the plate being of narrow width relative to the diameter of the tank, and being curved coaxially of the chamber through a distance not materially greater than one-half of a circle. 7

8. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a chamber extending above the normal liquid level in the tank, for confining air and for utilizin the said air to cushion movement of liquid within the said body, the said chamber communicating with the interior of said body and being of sufiicient area to permit displacement of such quantity of liquid lading as to materially dampen bufling forces, and means operative to permit relatively free flow of liquid into said chamber but retarding backflow therefrom.

9. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, an airconfining chamber disposed above the normal liquid level and communicating with the tank-like body, the chamber being of sufiicient area to permit displacement of such quantity of liquid lading as to materially dampen bufling stresses, and a venting de vice leading from the lower portion of said chamber at a point adjacent to the normal liquid level in the tank.

10. A vehicle having a tank-like body of elongated form disposed in parallelism with the line of movement of the vehicle, a chamber disposed above and communicating with the interior of said body, the said chamber communicating with the interior of the said body and being of sufficient area to permit displacement of such quantity of liquid lading as to materially dampen buffing forces, and means operative to permit relatively free flow of liquid into said chamber but retarding backflow therefrom.

In testimony whereof I, the said LOUIS E. ENDSLEY, have hereunto set my hand.

LOUIS E. ENDSLEY. 

